The present invention relates to an aircraft flight data management system and, more particularly, to an on-board data acquisition, storage and transmission system.
It is common for aircraft to generate records of operational and performance data for each flight of the aircraft. The data are utilized in the event of an accident or an incident and to assist in maintenance of the aircraft by detecting faulty components or gradual deterioration of a system or component. The data may also be used to improve efficiency of the operation, to optimize aircraft utilization, to assist in reviewing crew performance, and to assist in logistical planning activities such as scheduling and routing.
Aircraft data are typically gathered by a digital flight data acquisition unit (DFDAU). The DFDAU is the interface unit between all of the aircraft sensors and data buses and the flight data recorder (FDR) which stores the data on magnetic or magnetic-optical media on older aircraft. Newer aircraft utilize digital solid-state memory media. When the aircraft lands, ground personnel board the aircraft, remove the media or download the data from memory, and physically mail the media to a flight operations center (FOC). The manual removal and posting of the data adds a significant labor cost, yields less than desirable data delivery reliability, and results in a significant time delay before the data are useful for analysis.
It is known to use radio frequency (RF) transmissions to transmit data relating to an aircraft. Such teachings, however, require substantial investments to construct the RF transmission systems required for such a system to work. Furthermore, it is very expensive to create redundancy in such a system.
It is also known to transmit data relating to an aircraft via a telephone system located in a terminal. Such a system, however, requires that the aircraft be docked at the gate before transmission begins, thereby resulting in a substantial delay in the transmission. Furthermore, such a system requires an added step of transmitting the data from the aircraft to the terminal telephone system, increasing the cost of installing, operating, and maintaining such a system.
In another prior art system, described in U.S. Pat. No. 6,181,990, aircraft data is recorded and transmitted using a cellular telephony infrastructure. The system is designed to transmit all digitally recorded flight data as a single file which may typically include 40 megabytes of data. A compression utility is included to reduce the size of the file being transmitted and to reduce transmission time. The data may be encrypted. The data is processed into datagrams which are assembled into UDP/IP packets, transmitted over a cellular communications system, and received at a flight operations centre, where the packets are reassembled, decompressed and unencrypted. This system is unwieldy because of the volume of data being transmitted and because cellular data transmission may result in significant data loss.
Thus, there is a need in the art for an aircraft data transmission system that reliably and automatically transfers pertinent flight data from an aircraft to a remote location with little or no human involvement.